Marine Weather and Tide Forecast for Weskan, KS

SHORT TERM /THROUGH WEDNESDAY NIGHT/
Issued at 1230 PM MDT Sun Sep 20 2026

Still expecting isolated to widely scattered thunderstorms to develop later this afternoon and this evening in northeast Colorado. CAMs seem to be favoring the Palmer Divide area near Limon, with those storms spreading east and southeast through the evening hours. More isolated development will be possible in the remainder of northeast Colorado. Due to the cloud cover in Kansas and Nebraska, storms will have a difficult time making it much further east than the Colorado/Kansas border area. The environment will be highly sheared, bulk shear values are around 50 kts, due to a speed max moving through the base of the upper trough. MLCAPE values will be up to 1500 j/kg in Colorado. Those parameters support supercells capable of producing large hail of golf ball size or greater, damaging wind gusts, and a few tornadoes. Flash flooding will also be possible with the cluster of storms moving off the Palmer Divide into areas south of Interstate 70, which had areas of heavy rain last night. Those storms may persist well into the overnight hours as they gradually move south, sustained by a southwesterly low level jet and associated isentropic lift. Patchy fog will develop in the entire area by sunrise.

Monday will see a zonal flow develop in the wake of the departing upper low with subtle height rises by the afternoon.
At the surface, light northwest winds will follow a weak frontal passage in the morning, helping scour out the low clouds and fog. A few very isolated light showers or a thunderstorm may pop up in the afternoon, mainly near the frontal boundary south of Interstate 70, where instability will peak at less than 500 j/kg. Severe storms are not expected.

The upper ridge will amplify into the Central Plains on Tuesday.
The ridge axis will be just east of the area, resulting in southwest flow over the High Plains. Scattered afternoon storms will develop in southeast Colorado and along the Front Range in a corridor of weak instability and about 30 kts of deep layer shear. Mean storm motions will take them mainly northeast, with a low probability of reaching the area Tuesday night. If they do, it would be in a weakening stage with the loss of instability after sunset. Once again, severe storms are not anticipated.

The upper ridge settles into east Texas on Wednesday, with increasing southwesterly flow over the Central High Plains. The instability axis remains over northeast Colorado, but weaker compared to previous days and generally less than 500 j/kg, though there is a slight uptick in deep layer shear to 40 kts with the increased flow aloft. Models suggest fairly numerous showers and a few isolated thunderstorms developing in the afternoon with best chances in Colorado, then moving into the rest of the area Wednesday night. Latest probabilities for receiving at least 0.50" inches of rainfall Wednesday night are around 40-50% for areas south of Highway 40, tapering off to around 20% along the Highway 83 corridor into Nebraska, with less than 20% elsewhere.

Temperatures through the period remain slightly below normal with highs in the low to mid 70s and lows in the 50s. Normal highs for this time of the year are in the upper 70s.

LONG TERM /THURSDAY THROUGH SUNDAY/
Issued at 236 PM MDT Sun Sep 20 2026

Confidence is high that a longwave ridge is expected to influence the county warning area (CWA) Thursday through Saturday morning.
Ensemble guidance is in agreement of the ridge axis positioning over the Missouri River Valley placing the Tri-State area in southwest flow aloft. This feature should amplify a bit then move off to the east through Saturday night, bringing zonal westerly flow through at least next Sunday. A weak 500 mb jet accompanies this ridge but exits the region by Saturday. Surface low pressure forms Friday, influencing the area through the end of next weekend. Medium confidence exists of a frontal boundary impacting the area Thursday ushering in Probability of Precipitation (PoPs) chances heading into the weekend.

With respect to PoPs, rain is likely (60-80%) early Thursday as the front moves to the east. Rain chances for the afternoon/evening drop off a bit but persist with 30-50% chances for the CWA Friday's chances sit at around 25-40% as the system exits our CWA
Precipitation is unlikely Saturday as the upper-level pattern settles into zonal flow. Finally, Sunday presents a slight chance of rain (20-30%) during the evening as a shortwave passes through.
Dewpoints are forecasted in the upper 50s/low 60s so ample moisture will be present for rain and thundestorms. Model guidance does project a low instability, low shear environment during the four-day forecast period though so confidence in severe weather is low at this point in time.

High temperatures are expected to be near the seasonal average for this time of the year for the Tri-State area heading into the weekend. Highs in the mid 70s to mid 80s are likely for the entire forecast period. Saturday/Sunday should be a bit warmer (low to mid 80s) than Thursday and Friday (mid to upper 70s). Surface winds should be modest for Thursday and Friday blowing in at 5-15 mph from the southeast, gusting up to 20 mph. Winds Saturday are forecasted from the south at 5-10 mph gusting to 15 mph. Last but not least, Sunday's winds are anticipated to be 10-15 mph from the southeast, gusting up to 20 mph.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/
Issued at 1117 AM MDT Sun Sep 20 2026

Low clouds will gradually lift through the afternoon at KGLD and KMCK, with MVFR ceilings through about mid afternoon, with perhaps a few hours of VFR at both locations by late afternoon.
Isolated to widely scattered thunderstorms may impact KGLD this evening with brief gusty winds and reduced visibility in rain.
The low ceilings will quickly return this evening and persist through the rest of the night, before gradually lifting Monday morning. Patchy fog will develop as well.

GLD WATCHES/WARNINGS/ADVISORIES
KS...None.
CO...None.
NE...None.